With a conventional television set and remote control unit, the flow of information is one-way only, namely, from the remote control unit to the television. The remote control unit may signal the television set to change the volume, change the channel being received by the television, etc. In this way, the remote control unit can be used to control the television set. The remote control may also be used to control peripheral devices such as video cassette recorders, video disk players and audio equipment connected to the television set.
However, in order to prevent the television for responding incorrectly to the signals from the remote control unit, the television set is typically programmed not to respond to the remote control unit until the same instructional signal has been received from the remote control unit a predetermined number of times. For example, when the user presses a button on the remote control unit to change the channel, the remote control unit will automatically signal the television to make the indicated channel change a number of times. When the television receives the same command from the remote control redundantly, the television presumes it is correctly receiving the transmission from the remote control unit and executes the instructions received.
This safeguard helps insure that the television has properly understood and received the signal from the remote control unit and prevents mistakes in controlling the television. However, the requirement that the television wait for identical redundant signaling from the remote control unit necessarily slows the response of the television set to the remote control.
Additionally, with the advent of cable television, satellite television and digital television broadcasts, the amount of programming from among which a viewer can choose is tremendous. For example, one digital channel may carry several different programs, or sub-channels, simultaneously. This proliferation of programming makes it more and more difficult for a viewer to locate the programming he or she most desires to see.
While a conventional remote control unit allows the viewer to control the television set from across the room, it does not assist the viewer in navigating among the many channels available to find the most desired programming. For example, when tuning a digital channel which carries several sub-channels, the viewer must first select the digital channel. The television will then tune the digital channel. One of the sub-channels will be indicated as the default sub-channel, and the television will display the programming on the default sub-channel.
Thus, the user will then have to indicate whether a different sub-channel is desired. The user may do this by having the television's on-screen display (OSD) list the sub-channels available from which the user can select. However, this arrangement raises several problems.
First, the OSD is displayed over the programming on the default sub-channel. This obscures the programming on the default sub-channel so that it cannot readily be observed and evaluated by the user if the user so desires.
Second, the television may not begin to display the programming on the default sub-channel until all the sub-channel information has been acquired. This necessarily delays the acquisition and display of the default sub-channel, which may be the only channel in which the viewer is interested.
Consequently, there is a need in the prior art for a remote control unit and television set which can more rapidly and readily execute the user's instructions and which can assist the user in navigating among the variety of available programming.